This research proposal is directed toward a continuation of our studies on carbohydrate-protein interaction. We will investigate two species of carbohydrate-binding proteins: lectins and immune antibodies raised against carbohydrate-containing antigens. We will study the physical-chemical and biological properties of the 5 alpha-D-galactosyl-binding isolectins from Bandeiraea simplicifolia seeds. We will test our hypothesis, that the B subunits of these tetrameric glycoproteins are converted by proteolytic cleavage to the A subunits. The lectins from the seeds of wild cucumber (Echinocystis lobata), Datura stromonium (also D. talula and D. goldroni), and a third lectin, BS III from B. simplicifolia seeds will be characterized. The subunit structure, carbohydrate-binding activity and large-scale testing of the lima bean lectin as a serological substitute for human anti-A antiserum will be studied. A new solid phase approach to affinity labeling of lectins will be evaluated. Nitroxide-containing spin labels will be covalently linked to sugars and their interaction with lectins will be studied by electron-spin resonance. Antibodies to the disaccharide unit of collagen will be raised in rabbits and will be examined for their cross-reactivity with collagen.